For the price, or the Tamron move, zoom to take pictures "classic" (18mm and up to 24mm) This lens allows the mounted kept at the various pictures (eg family gatherings or I left up instead of 18-55mm). This allows one to "cover" all types of possible photos indoors or outside in the garden for example, and power when you want to take an overall picture (following the inclination of the device, the outlook is perfectly parralèles, as if this was not a wide angle. And conversely, in "forcing" on the position and inclinaision taking, clichés can have a very special effect and "fun").
The autofocus is quick and remains relatively quiet and does not interfere with anything people, even when taking pictures next to them in a conversation.
The lens has a motorized auto focus and using the D3100 on this is also a plus.
For the price, it is everyone has to be tried to see if their desire and pleasure is large enough to afford this "toy" that is installed in the course of major.
Personally, wishing to urban photo, panoramic, landscape, interior, etc ... it is perfect for use as I would.
For fans :)